Communication system and method of operating the same

Abstract

There is provided a communication system, comprising a transmission unit to be worn at a user's body at or below the user's neck for transmitting audio signals via an inductive link; and an earpiece to be worn at least in part in the user's ear canal including a receiver unit for receiving audio signals via said inductive link from the transmission unit, an audio signal processing unit for processing audio signals received by the receiver unit, and a loudspeaker stimulating the user's hearing according to the processed audio signals; wherein said inductive link is an amplitude modulation inductive link having a carrier frequency of from 100 kHz to 30 MHz.

1 . A communication system, comprising:
 a transmission unit to be worn at a user's body at or below a neck of said user for transmitting audio signals via an inductive link; and   an earpiece to be worn at least in part in an ear canal of said user including a receiver unit for receiving audio signals via said inductive link from said transmission unit, an audio signal processing unit for processing audio signals received by said receiver unit, and a loudspeaker for stimulating a hearing of said user according to said processed audio signals;   wherein said inductive link is an amplitude modulation inductive link having a carrier frequency of from 100 kHz to 30 MHz.   
   
   
       2 . The system of  claim 1 , wherein said transmission unit comprises a low-pass filter for filtering said audio signals prior to undergoing amplitude modulation, which is adapted to ensure that a modulated audio signal bandwidth is less than 10 kHz. 
   
   
       3 . The system of  claim 1 , wherein said transmission unit comprises an antenna designed as an inductive loop selected from the group consisting of a loop to be worn around said user's neck, a loop to be worn around said user's arm and a loop to be worn over said user's shoulder. 
   
   
       4 . The system of  claim 1 , wherein said transmission unit comprises an automatic-gain-control amplifier adapted for avoiding over-modulation of said inductive link. 
   
   
       5 . The system of  claim 1 , wherein said transmission unit comprises a signal detector for detecting the presence of audio signals to be transmitted via said inductive link. 
   
   
       6 . The system of  claim 5 , wherein said signal detector is adapted to disable said transmission unit during times when no presence of audio signals to be transmitted via said inductive link is detected. 
   
   
       7 . The system of  claim 6 , wherein said signal detector is adapted to switch on and off a power amplifier used for amplifying audio signals to be transmitted via said inductive link according to a presence of audio signals to be transmitted via said inductive link. 
   
   
       8 . The system of  claim 6 , wherein said signal detector is adapted to detect a presence of audio signals to be transmitted via said inductive link with an attack time of less than 10 msec. 
   
   
       9 . The system of  claim 6 , wherein said signal detector is adapted to disable said transmission unit with a release time constant of from 100 to 3000 msec. 
   
   
       10 . The system of  claim 1 , wherein said receiver unit comprises an antenna, an amplitude modulation demodulator and a band-pass filter having a bandwidth substantially equal to a modulated audio signal bandwidth, said band-pass filter being adapted for filtering signals received by said antenna prior to being demodulated by said demodulator. 
   
   
       11 . The system of  claim 1 , wherein said audio signal processing unit comprises a digital signal processor for processing audio signals demodulated by a demodulator. 
   
   
       12 . The system of  claim 11 , wherein said digital signal processor is adapted to band-pass filter said audio signals demodulated by said demodulator. 
   
   
       13 . The system of  claim 11 , wherein said digital signal processor is adapted to process said audio signals demodulated by said demodulator both in time domain and in frequency domain. 
   
   
       14 . The system of  claim 11 , wherein said digital signal processor applies a gain model to control a maximum output power delivered to said loudspeaker. 
   
   
       15 . The system of  claim 11 , wherein said audio signal processing unit comprises a non-volatile memory for storing audio signal processing parameters to be used by said digital signal processor. 
   
   
       16 . The system of  claim 1 , wherein the system comprises a receiver device for receiving audio signals via a wireless link, which is connected to or integrated with said transmission unit, said receiver device being adapted to supply said received audio signals to said transmission unit. 
   
   
       17 . The system of  claim 16 , wherein said wireless link is a radio frequency link. 
   
   
       18 . The system of  claim 16 , wherein said transmission unit is connected to said receiver device via a cable. 
   
   
       19 . The system of  claim 18 , wherein said transmission unit is powered by said receiver device via said cable. 
   
   
       20 . The system of  claim 16 , wherein said transmission unit comprises a microphone for capturing audio signals from a voice of said user. 
   
   
       21 . The system of  claim 20 , wherein said wireless link is bidirectional and wherein said audio signals captured by said microphone of said transmission unit are supplied to said receiver device for being transmitted via said wireless link. 
   
   
       22 . The system of  claim 1 , wherein said earpiece is adapted to be worn completely in said user's ear canal. 
   
   
       23 . A method of operating a communication system comprising a transmission unit to be worn at a body of a user at or below a neck of said user and an earpiece to be worn at least in part in an ear canal of said user, comprising
 supplying audio signals to said transmission unit,   transmitting said audio signals from said transmission unit to said earpiece via an inductive link, and   stimulating a hearing of said user via said earpiece according to audio signals received by said earpiece,   wherein said inductive link is an amplitude modulation inductive link having a carrier frequency of from 100 kHz to 30 MHz.